1. Technical Field
The present invention relates to a wafer polishing carrier apparatus and to chemical mechanical polishing equipment employing the same, and more particularly, to a wafer polishing carrier apparatus for pressurizing a wafer on a platen with a given pressurized force and moving it, and chemical mechanical polishing equipment employing the same.
2. Description
Recent rapid developments in the field of information communication and a popularization of information on information media, such as computer etc., have brought about a remarkable growth in semiconductor devices. The semiconductor device simultaneously requires a high-speed operation and a large capacity of storage in view of increased demands in functionality. This causes increased burdens on and cost of manufacturing technology of the semiconductor device in an effort to improve integration, reliability and response speed etc. The manufacturing technology of semiconductor device includes a deposition process for forming a processing layer on a wafer, and a photolithography process and etching process for forming a processed-layer on the processing layer formed through the deposition and patterning it. Recently, a planarization process to uniformly planarize the surface of wafer with a step coverage is added.
The planarization process is generally performed by chemical mechanical polishing equipment useful for mechanically abrading a wafer and also chemically polishing the wafer by supplying slurry onto the surface of the wafer. The chemical mechanical polishing equipment is adapted to pressurize the wafer disposed on a platen to which a polishing pad having a given friction coefficient adheres, by a given pressurization force, and to polish the wafer. The wafer is adapted to horizontally move in a state of being pressurized onto the platen by a wafer polishing carrier apparatus, as a polishing head device. At this time, the wafer and the platen relatively rotate, abrading the surface of wafer and the polishing pad associated with the platen. Thus, in the current state of chemical mechanical polishing equipments according to conventional art, a relative movement direction of wafers or platens may be designed with a partial difference.
The chemical mechanical polishing equipment described below according to a conventional art is configured to revolve a wafer around the platen and simultaneously rotate it on its own axis by a given rotation speed. The revolution versus rotation rate of the wafer is determined as the same or similar rate. The wafer polishing carrier apparatus is configured to pressurize the wafer by a given pressurization force or adsorbing it by a given adsorption force so that the wafer is revolved around the platen or rotated on its own axis.
The wafer polishing carrier apparatus is configured to include a drive rotary union and a driven rotary union that are engaged with each other to rotate, so as to revolve, the wafer around the platen and rotate it on its own axis. The wafer polishing carrier apparatus may be configured to further include a carrier for holding the wafer at an end part of the driven rotary union by using a fluid, such as air flowing through plural rotary unions. Here the carrier is adapted to adsorb or detach the wafer by using a pressure of fluid provided through a conduit connected with plural rotary unions.
The drive rotary union and the driven rotary union each comprise a mechanical seal part configured in a direction vertical to each rotation axis to seal and flow the fluid supplied by a given pressure. The mechanical seal part is adapted to prevent the fluid from leaking from a portion of an axis or rotation body rotating by a given speed. Here the mechanical seal part has a structure for providing a complete adhesion of a metal part and a carbon or antimony portion through a sliding movement so as to maintain a liquid-tightened state.
However, in a wafer polishing carrier apparatus and chemical mechanical polishing equipment employing the same, pollution material such as a carbon or antimony component generated by an abrasion of each mechanical seal part of drive rotary union and driven rotary union leaks onto a platen, thus causing a process error of chemical mechanical polishing processor, such as scratch on wafer, resulting in a decrease of production yield.
Furthermore a partial pollution from the pollution material is easy to generate on a polishing pad and in a narrow inner diameter portion of conduit adapted in a lower part or end part of carrier coupled to the drive rotary union and driven rotary union, thus it is frequently required to perform cleaning work of the conduit and polishing pad, causing a decrease of productivity.